High-Performance Photodetector from p-n Junction of Vertically Aligned SnS₂ and Reduced Graphene Oxide

Semiconducting 2D transition metal dichalcogenides (TMDC) became very popular in photodetection due to their high mobility and high rate of generating electron and hole pairs. Over the past decade, MoS2 and WS2 became the most popular TMDC for several applications. On the other hand, due to the complex synthesis process compared to MoS2 and WS2, SnS2 became a less popular 2D material for photodetection. We synthesized vertically aligned SnS2 flakes by a chemical vapor deposition (CVD) process with three temperature zones with controlled argon (Ar) gas flow. Pristine SnS2-based devices are not very suitable for photodetection applications because of their low photo-to-dark current ratio (Iph/Idark), high response time, and low stability. So, they need to be decorated with oppositely doped materials. We decorated pristine SnS2-based devices with rGO nanoparticles, which significantly increased the device’s performance. We found a high responsivity (R) of 1.33 A/W, detectivity (D) of 6.95 × 1011 Jones, Iph/Idark of 102, and a rise time of 0.241 ms (fall time of 1.318 ms) with the rGO decorated SnS2-based device.